Pityriasis Rubra Pilaris

What is Pityriasis Rubra Pilaris?

Pityriasis rubra pilaris (PRP) is a rare skin disorder characterized by inflammation and scaling. The exact cause of PRP is not known. This condition has 6 distinct variations and can affect both children and adults. Some common features across all types include hardening and scaling of the skin on the palms and soles, and small skin bumps grouping together into clear bordered patches of varying sizes. These patches often have a reddish-orange color and shed non-sticky flakes.

There are also more general types of PRP that have unaffected skin areas known as “islands of sparing”, a key feature which sets PRP apart. However, diseases that imitate PRP like psoriasis or mycosis fungoides may occasionally show this feature, particularly in patients with extensive skin redness.

People with PRP can experience a wide range of symptoms, from mild conditions limited to the outer parts of the arms and legs, to intense redness covering 90% to 100% of the body. This redness can result in severe itchiness, skin tightness, burning sensations, stinging, and pain. Some cases of PRP resolves on its own and does not show any symptoms. But when the disorder is chronic and causes symptoms, ongoing treatment is necessary. This usually involves using topical treatments for symptom relief coupled with full-body treatment to reduce inflammation.

What Causes Pityriasis Rubra Pilaris?

The exact cause of PRP, a type of skin disease, is still unknown. However, there have been cases where PRP-like skin changes have been linked to certain drugs, particularly ponatinib or other similar drugs. Even though PRP has been seen at the same time as viral infections, vaccines, injuries, and other diseases, these aren’t always the case and figuring out whether these events are causing PRP or it’s just a coincidence is challenging.

There are also a number of instances where PRP has been found together with cancer, even though the skin symptoms of PRP in these cases tend to be out of the ordinary, and the related tumors vary. Nevertheless, it is crucial to note that these associations don’t necessarily mean that these factors are the cause of PRP.

Risk Factors and Frequency for Pityriasis Rubra Pilaris

Pityriasis rubra pilaris (PRP) is a skin condition that can be found all over the world. Depending on the country, the rate of people visiting a dermatologist for the first time for PRP can vary. It’s found in about 1 in every 500 new dermatology visits in Kenya, 1 in 5,000 visits in Great Britain, and 1 in 50,000 visits in India. Both males and females can have PRP, with some studies showing a slightly higher occurrence in males.

The condition can occur at any age, but generally, it seems to be more common in two age groups: individuals in the first to the second decade of life and those in the fifth to the sixth decade of life. PRP usually occurs in people with no family history of the condition, but in some instances, it can run in families. When it’s inherited, the pattern usually follows what’s known as autosomal dominant inheritance, which is linked to changes in a gene called CARD14.

• Pityriasis rubra pilaris (PRP) is a skin condition found globally.
• Its prevalence varies by country – it’s found in about 1 in every 500 new dermatology visits in Kenya, 1 in 5,000 visits in Great Britain, and 1 in 50,000 visits in India.
• Both genders can be affected with a slight male predominance.
• PRP can occur at any age, but there are peak incidences in the first to second decades of life and the fifth to sixth decades of life.
• Most PRP cases occur sporadically, but it can also run in families.
• When inherited, the pattern is usually autosomal dominant, linked to changes in the CARD14 gene.

Signs and Symptoms of Pityriasis Rubra Pilaris

Pityriasis Rubra Pilaris (PRP) is a skin condition that can manifest in different ways. Historically, doctors have separated PRP into several subtypes according to Griffiths’ classification, which was based on factors such as when the condition starts (childhood versus adulthood), the character of the skin lesions, and their distribution. More recently, a further subtype was added for PRP associated with HIV, with another separate category proposed for early-onset PRP linked to changes in the CARD14 gene.

Here are the types of PRP:

• Type I: Classic adult-onset
• Type II: Atypical adult-onset
• Type III: Classic juvenile-onset
• Type IV: Circumscribed juvenile-onset
• Type V: Atypical juvenile-onset
• Type VI: HIV-associated
• CARD14-associated papulosquamous eruption (CAPE)

All types of PRP have certain common features, including palmar and plantar hyperkeratosis (thickening of the skin on the palms and soles), and skin bumps that join together to form clearly outlined red-orange plaques. People with localized PRP often have mild itchiness, while those with widespread PRP can experience intense itching and pain that interferes with their day-to-day lives and mental well-being, sometimes even raising the risk of suicidal thoughts.

Each PRP type has distinct characteristics. For instance, type I PRP is the most common in adults, initially appearing like fine dry skin and redness on the scalp, which might be mistaken for another type of skin inflammation called seborrheic dermatitis. Over time, additional skin changes develop and spread downwards. Type II PRP is not as common and appears similar to classic PRP but with more eczema-like plaques and scaly skin. Type III PRP is similar to type I PRP but starts in childhood and less often results in erythroderma (widespread skin redness and scaling). Type IV PRP is localized and common in younger children, while type V PRP is a long-lasting, widespread version diagnosed in early childhood. Type VI PRP is associated with HIV. Lastly, the CARD14-associated papulosquamous eruption (CAPE) is linked to a specific gene variation and may look like either psoriasis or classic PRP.

Widespread or erythrodermic PRP can lead to additional problems like lower eyelid drooping which can cause corneal inflammation, hearing limitations due to wax buildup in the ear canal, runny nose, hair loss, swelling of the limbs, and issues controlling body temperature. Patients might also experience intense itching, a burning skin sensation, joint pain, sleep disruptions, and tiredness, which could lead to a range of everyday challenges. Severe PRP can impact mental health, leading to depression, embarrassment, loneliness, low self-esteem, memory loss or difficulty thinking, and suicidal thoughts.

Testing for Pityriasis Rubra Pilaris

To check your skin, a doctor might perform a full skin examination, including feeling for any swollen glands (lymph nodes) that could point to cancer, which would change the diagnosis, particularly in adults. If they find something, they usually do at least two skin biopsies to get samples from areas of the skin with hair-filled bumps or reddened, scaled patches. Pityriasis Rubra Pilaris (PRP), a skin disorder, is diagnosed based on its appearance and the features seen under the microscope in the biopsied skin sample. We don’t have any blood tests or measurements on skin biopsy samples to help with the diagnosis. However, since PRP has been rarely linked to HIV, it might be a good idea to get tested for HIV too.

Treatment Options for Pityriasis Rubra Pilaris

Pityriasis rubra pilaris (PRP) is a skin condition that can be difficult to treat, and there are currently no treatments approved specifically for it by the US Food and Drug Administration. However, some general recommendations can be made to help manage symptoms.

All patients can benefit from frequent application of simple creams or ointments throughout the day to soothe the skin and repair its barrier. These are known as emollients and can provide much-needed comfort. Steroid creams may be tried, but they might not be more beneficial than simple moisturizers. For thickened skin on the palms of the hands and soles of the feet, special creams such as those containing urea, salicylic acid, or alpha-hydroxy acid could be beneficial.

For patients with widespread PRP affecting large areas of the body, a special waterproof suit may help with body temperature adjustment, skin barrier protection, and discomfort from clothes. Bathing can be as often as tolerated, but the experience can vary – some people find relief from long, warm baths, while others can’t stand the sensation of water on their skin.

For those with more severe PRP, it’s often recommended to try treatments that work throughout the whole body. There is no definitive evidence for the best choice of treatment, but a few have shown promise in trials, despite potential side effects. One such medication is isotretinoin, which significantly improved the condition for around 58% of patients in a study. However, it can be difficult to tolerate due to significant side effects like dry skin, muscle aches, and potential risks of congenital disabilities if taken in pregnancy.

In recent years, several medications that target specific parts of the immune system have shown promise in treating PRP. For example, the drugs ixekizumab and secukinumab, which target a molecule known as IL17A, resulted in around 61.3% and 55.6% improvements in clinical symptoms respectively, in separate studies. They appeared to be well-tolerated with no reported serious side effects.

Certain other drugs such as methotrexate and acitretin are sometimes suggested as the first choice of treatment for PRP, though systematic trials have not been performed and reviews suggest they may be less effective than some other treatments. It’s worth noting that oral corticosteroids such as prednisone don’t appear to be effective for PRP and most other forms of erythroderma (reddened and inflamed skin).

Narrow-band UVB phototherapy is rarely helpful for PRP since it can make symptoms worse for most patients. However, around 10% of patients may respond well to phototherapy. After a patient responds to therapy and their condition improves, treatment can usually be discontinued, and many patients will remain symptom-free.

What else can Pityriasis Rubra Pilaris be?

The process of diagnosing Pityriasis Rubra Pilaris (PRP), a skin disorder, can vary and often overlaps with other conditions, mainly psoriasis. It can be challenging to distinguish between PRP and psoriasis, especially since psoriasis also has a rare form linked to hair follicles, which has similar attributes to PRP. Nevertheless, psoriasis doesn’t affect the palms or soles (palmoplantar keratoderma), which can act as a distinguishing factor.

There are several other conditions to consider when diagnosing PRP. These include:

• Scalp conditions: Early signs of PRP in the scalp can sometimes resemble seborrheic dermatitis or allergic contact dermatitis due to its appearance.
• Palmoplantar keratoderma: The waxy surface and unique red-orange color found in PRP might help differentiate it from similar conditions like psoriasis, Bazex syndrome, and mycosis fungoides.
• Erythroderma: This is a widespread redness of the skin that can be hard to diagnose due to its similarity with many inflammatory conditions, including PRP, psoriasis, mycosis fungoides, Sezary syndrome, atopic dermatitis, allergic contact dermatitis, paraneoplastic erythroderma, and more. Special care is needed in diagnosing PRP in such cases as it can strongly resemble certain conditions like mycosis fungoides.
• Joint or muscle pain: People with PRP often report pain in joints, and occasionally some cases may involve inflammatory arthritis. If patients report weakness, Wong-type dermatomyositis, which presents characteristics of both PRP and dermatomyositis, should be considered.

Diagnosing PRP can be complex and requires thorough examination. In some cases, even a personal or family history of psoriasis might be present, making accurate diagnosis more challenging. A biopsy can often provide helpful information.

What to expect with Pityriasis Rubra Pilaris

PRP, or Pityriasis Rubra Pilaris, does not increase the risk of death. However, it can significantly affect a person’s quality of life, particularly if the disease is severe.

In cases of PRP that occur spontaneously in adults, the disease gradually goes away in about half of the patients over a period of months to years, typically within around three years. Once the symptoms go away, they rarely come back. However, for the remaining 50% of patients, they may have to live with the disease for their entire life.

Earlier studies suggested that the spontaneous disappearance of symptoms occurred with 81% of patients who suffered from type I or “classical” onset PRP in three years. For those experiencing type II or “atypical” onset PRP, the chances were lower at 20%. However, more recent research has hinted that these categories might not be as distinct as thought. It’s also hard to predict the improvement of patients with type II PRP since their diagnosis includes the consideration of persistent, or long-lasting, disease.

PRP that starts in early childhood, before the age of 2, often relates to variations in genes, and the disease will be a lifelong condition in these cases. Studies of spontaneous cases of PRP in children show rates of complete resolution or disappearance of symptoms ranging from 43% to 80%.

Possible Complications When Diagnosed with Pityriasis Rubra Pilaris

PRP, or Pityriasis Rubra Pilaris, is a skin condition that affects a person’s quality of life depending on how severe their symptoms are. Severe forms of PRP can lead to discomfort ranging from problems with using everyday tools due to hard skin on palms, difficulties walking because of the condition affecting feet, to itching, pain, and abnormal feelings in the skin that cause problems with wearing clothes. These specific symptoms may make it hard for individuals with PRP to leave the house or complete their daily activities at home or work.

• Difficulty using tools and touchscreen devices due to hard skin on palms
• Pain while walking
• Itching and pain, leading to trouble wearing clothes
• Problems with leaving the house or doing daily tasks at home or at work

People suffering from PRP, especially from moderate to severe forms, often report mental health impact. This impact can involve feelings of depression, anxiety, embarrassment, loneliness, low self-esteem, and memory fog. Some studies report that individuals with PRP might also have suicidal thoughts.

However, in patients where the disease fully disappears, complications are quite rare. Some individuals might experience incomplete hair regrowth or a persistent feeling of memory loss or “brain fog,” but it’s not typical for the skin to exhibit scarring.

• Feelings of depression, anxiety, loneliness, low self-esteem
• Memory fog
• Possible suicidal ideation
• Possible incomplete hair regrowth and persistent memory fog after disease resolution

Preventing Pityriasis Rubra Pilaris

There is no established connection between PRP (Pityriasis Rubra Pilaris) and lifestyle choices or other existing health problems. It’s important that all patients are made aware of the PRP Alliance, which is a nonprofit organization that offers support to patients. It was established in 2013. The PRP Alliance provides a ‘PRP Survival Guide’ which is written by and for individuals dealing with PRP, to help navigate living with the condition.